Bluetooth Low Energy Shield servo

Oggi ho provato la Bluetooth Low Energy Shield servo ossia la Bluetooth Low Energy Shield con tre servocomandi di quelli comunemente usati in modellismo.

Il controllo dei servo, come sai, avviene mediante l’uso dei pin pwm di arduino e l’uso della classe Servo.h ed i servo standard sono in grado di eseguire movimenti in gradi da 0 a 180.

L’app per smartphone fornita dalla redbear lab ti offre la possibilità di controllare le uscite pwm anche come servocomandi inviando i gradi al posto dei valori 0-255 usati con i pin pwm.

Questo approccio rende più semplice lo sketch in quanto puoi usare direttamente il valore proveniente dall’App per inviarlo al servo senza dover intervenire per adattarlo da pwm a servo.

Il collegamento del  Bluetooth Low Energy Shield servo

Il collegamento dei servo è illustrato in molti miei tutorial e non presenta differenze per questo progetto.

Ciascun servo deve essere alimentato da 4.8v a 6v per cui puoi utilizzare i 5v di arduino e presenta un pin di controllo che devi collegare ad una uscita pwm libera della Bluetooth Low Energy Shield servo, io ho usato i pin 3,5 e 6 come per il precedente articolo:

I servo che ho utilizzato io sono poco onerosi dal punto di vista energetico e posso alimentarli tutti collegandoli ai 5v di arduino:

Lo sketch di test

lo sketch è sempre il “BLEControllerSketch” fornito con la libreria di controllo e gli esempi, lo riporto per conoscenza e ti invito a leggere la spiegazione line aper linea in questo articolo:

/*
 
Copyright (c) 2012, 2013 RedBearLab
 
Permission is hereby granted, free of charge, to any person 
obtaining a copy of this software and associated documentation 
files (the "Software"), to deal in the Software without restriction, 
including without limitation the rights to use, copy, modify, merge, 
publish, distribute, sublicense, and/or sell copies of the Software, 
and to permit persons to whom the Software is furnished to do so, 
subject to the following conditions:
 
The above copyright notice and this permission notice shall be included 
in all copies or substantial portions of the Software.
 
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. 
IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, 
DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT 
OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE 
OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 
*/
 
#include <Servo.h>
#include <SPI.h>
#include <boards.h>
#include <RBL_nRF8001.h>
#include <services.h>
#include "Boards.h"
 
#define PROTOCOL_MAJOR_VERSION   0 //
#define PROTOCOL_MINOR_VERSION   0 //
#define PROTOCOL_BUGFIX_VERSION  2 // bugfix
 
#define PIN_CAPABILITY_NONE      0x00
#define PIN_CAPABILITY_DIGITAL   0x01
#define PIN_CAPABILITY_ANALOG    0x02
#define PIN_CAPABILITY_PWM       0x04
#define PIN_CAPABILITY_SERVO     0x08
#define PIN_CAPABILITY_I2C       0x10
 
// pin modes
//#define INPUT                 0x00 // defined in wiring.h
//#define OUTPUT                0x01 // defined in wiring.h
#define ANALOG                  0x02 // analog pin in analogInput mode
#define PWM                     0x03 // digital pin in PWM output mode
#define SERVO                   0x04 // digital pin in Servo output mode
 
byte pin_mode[TOTAL_PINS];
byte pin_state[TOTAL_PINS];
byte pin_pwm[TOTAL_PINS];
byte pin_servo[TOTAL_PINS];
 
Servo servos[MAX_SERVOS];
 
void setup()
{
  Serial.begin(57600);
  Serial.println("BLE Arduino Slave");
   
  /* Default all to digital input */
  for (int pin = 0; pin < TOTAL_PINS; pin++)
  {
    // Set pin to input with internal pull up
    pinMode(pin, INPUT);
    digitalWrite(pin, HIGH);
 
    // Save pin mode and state
    pin_mode[pin] = INPUT;
    pin_state[pin] = LOW;
  }
 
  // Default pins set to 9 and 8 for REQN and RDYN
  // Set your REQN and RDYN here before ble_begin() if you need
  //ble_set_pins(3, 2);
   
  // Set your BLE Shield name here, max. length 10
  //ble_set_name("My Name");
   
  // Init. and start BLE library.
  ble_begin();
}
 
static byte buf_len = 0;
 
void ble_write_string(byte *bytes, uint8_t len)
{
  if (buf_len + len > 20)
  {
    for (int j = 0; j < 15000; j++)
      ble_do_events();
     
    buf_len = 0;
  }
   
  for (int j = 0; j < len; j++)
  {
    ble_write(bytes[j]);
    buf_len++;
  }
     
  if (buf_len == 20)
  {
    for (int j = 0; j < 15000; j++)
      ble_do_events();
     
    buf_len = 0;
  }  
}
 
byte reportDigitalInput()
{
  if (!ble_connected())
    return 0;
 
  static byte pin = 0;
  byte report = 0;
   
  if (!IS_PIN_DIGITAL(pin))
  {
    pin++;
    if (pin >= TOTAL_PINS)
      pin = 0;
    return 0;
  }
   
  if (pin_mode[pin] == INPUT)
  {
      byte current_state = digitalRead(pin);
             
      if (pin_state[pin] != current_state)
      {
        pin_state[pin] = current_state;
        byte buf[] = {'G', pin, INPUT, current_state};
        ble_write_string(buf, 4);
         
        report = 1;
      }
  }
   
  pin++;
  if (pin >= TOTAL_PINS)
    pin = 0;
     
  return report;
}
 
void reportPinCapability(byte pin)
{
  byte buf[] = {'P', pin, 0x00};
  byte pin_cap = 0;
                     
  if (IS_PIN_DIGITAL(pin))
    pin_cap |= PIN_CAPABILITY_DIGITAL;
             
  if (IS_PIN_ANALOG(pin))
    pin_cap |= PIN_CAPABILITY_ANALOG;
 
  if (IS_PIN_PWM(pin))
    pin_cap |= PIN_CAPABILITY_PWM;
 
  if (IS_PIN_SERVO(pin))
    pin_cap |= PIN_CAPABILITY_SERVO;
 
  buf[2] = pin_cap;
  ble_write_string(buf, 3);
}
 
void reportPinServoData(byte pin)
{
//  if (IS_PIN_SERVO(pin))
//    servos[PIN_TO_SERVO(pin)].write(value);
//  pin_servo[pin] = value;
   
  byte value = pin_servo[pin];
  byte mode = pin_mode[pin];
  byte buf[] = {'G', pin, mode, value};         
  ble_write_string(buf, 4);
}
 
byte reportPinAnalogData()
{
  if (!ble_connected())
    return 0;
     
  static byte pin = 0;
  byte report = 0;
   
  if (!IS_PIN_DIGITAL(pin))
  {
    pin++;
    if (pin >= TOTAL_PINS)
      pin = 0;
    return 0;
  }
   
  if (pin_mode[pin] == ANALOG)
  {
    uint16_t value = analogRead(pin);
    byte value_lo = value;
    byte value_hi = value>>8;
     
    byte mode = pin_mode[pin];
    mode = (value_hi << 4) | mode;
     
    byte buf[] = {'G', pin, mode, value_lo};         
    ble_write_string(buf, 4);
  }
   
  pin++;
  if (pin >= TOTAL_PINS)
    pin = 0;
     
  return report;
}
 
void reportPinDigitalData(byte pin)
{
  byte state = digitalRead(pin);
  byte mode = pin_mode[pin];
  byte buf[] = {'G', pin, mode, state};         
  ble_write_string(buf, 4);
}
 
void reportPinPWMData(byte pin)
{
  byte value = pin_pwm[pin];
  byte mode = pin_mode[pin];
  byte buf[] = {'G', pin, mode, value};         
  ble_write_string(buf, 4);
}
 
void sendCustomData(uint8_t *buf, uint8_t len)
{
  uint8_t data[20] = "Z";
  memcpy(&data[1], buf, len);
  ble_write_string(data, len+1);
}
 
byte queryDone = false;
 
void loop()
{
  while(ble_available())
  {
    byte cmd;
    cmd = ble_read();
    Serial.write(cmd);
     
    // Parse data here
    switch (cmd)
    {
      case 'V': // query protocol version
        {
          byte buf[] = {'V', 0x00, 0x00, 0x01};
          ble_write_string(buf, 4);
        }
        break;
       
      case 'C': // query board total pin count
        {
          byte buf[2];
          buf[0] = 'C';
          buf[1] = TOTAL_PINS; 
          ble_write_string(buf, 2);
        }        
        break;
       
      case 'M': // query pin mode
        {  
          byte pin = ble_read();
          byte buf[] = {'M', pin, pin_mode[pin]}; // report pin mode
          ble_write_string(buf, 3);
        }  
        break;
       
      case 'S': // set pin mode
        {
          byte pin = ble_read();
          byte mode = ble_read();
           
          if (IS_PIN_SERVO(pin) && mode != SERVO \
                                && servos[PIN_TO_SERVO(pin)].attached())
            servos[PIN_TO_SERVO(pin)].detach();
   
          /* ToDo: check the mode is in its capability or not */
          /* assume always ok */
          if (mode != pin_mode[pin])
          {              
            pinMode(pin, mode);
            pin_mode[pin] = mode;
           
            if (mode == OUTPUT)
            {
              digitalWrite(pin, LOW);
              pin_state[pin] = LOW;
            }
            else if (mode == INPUT)
            {
              digitalWrite(pin, HIGH);
              pin_state[pin] = HIGH;
            }
            else if (mode == ANALOG)
            {
              if (IS_PIN_ANALOG(pin)) {
                if (IS_PIN_DIGITAL(pin)) {
                  pinMode(PIN_TO_DIGITAL(pin), LOW);
                }
              }
            }
            else if (mode == PWM)
            {
              if (IS_PIN_PWM(pin))
              {
                pinMode(PIN_TO_PWM(pin), OUTPUT);
                analogWrite(PIN_TO_PWM(pin), 0);
                pin_pwm[pin] = 0;
                pin_mode[pin] = PWM;
              }
            }
            else if (mode == SERVO)
            {
              if (IS_PIN_SERVO(pin))
              {
                pin_servo[pin] = 0;
                pin_mode[pin] = SERVO;
                if (!servos[PIN_TO_SERVO(pin)].attached())
                  servos[PIN_TO_SERVO(pin)].attach(PIN_TO_DIGITAL(pin));
              }
            }
          }
             
  //        if (mode == ANALOG)
  //          reportPinAnalogData(pin);
          if ( (mode == INPUT) || (mode == OUTPUT) )
            reportPinDigitalData(pin);
          else if (mode == PWM)
            reportPinPWMData(pin);
          else if (mode == SERVO)
            reportPinServoData(pin);
        }
        break;
 
      case 'G': // query pin data
        {
          byte pin = ble_read();
          reportPinDigitalData(pin);
        }
        break;
         
      case 'T': // set pin digital state
        {
          byte pin = ble_read();
          byte state = ble_read();
           
          digitalWrite(pin, state);
          reportPinDigitalData(pin);
        }
        break;
       
      case 'N': // set PWM
        {
          byte pin = ble_read();
          byte value = ble_read();
           
          analogWrite(PIN_TO_PWM(pin), value);
          pin_pwm[pin] = value;
          reportPinPWMData(pin);
        }
        break;
       
      case 'O': // set Servo
        {
          byte pin = ble_read();
          byte value = ble_read();
 
          if (IS_PIN_SERVO(pin))
            servos[PIN_TO_SERVO(pin)].write(value);
          pin_servo[pin] = value;
          reportPinServoData(pin);
        }
        break;
       
      case 'A': // query all pin status
        for (int pin = 0; pin < TOTAL_PINS; pin++)
        {
          reportPinCapability(pin);
          if ( (pin_mode[pin] == INPUT) || (pin_mode[pin] == OUTPUT) )
            reportPinDigitalData(pin);
          else if (pin_mode[pin] == PWM)
            reportPinPWMData(pin);
          else if (pin_mode[pin] == SERVO)
            reportPinServoData(pin);  
        }
         
        queryDone = true; 
        {
          uint8_t str[] = "ABC";
          sendCustomData(str, 3);
        }
        
        break;
           
      case 'P': // query pin capability
        {
          byte pin = ble_read();
          reportPinCapability(pin);
        }
        break;
         
      case 'Z':
        {
          byte len = ble_read();
          byte buf[len];
          for (int i=0;i<len;i++)
            buf[i] = ble_read();
          Serial.println("->");
          Serial.print("Received: ");
          Serial.print(len);
          Serial.println(" byte(s)");
          Serial.print(" Hex: ");
          for (int i=0;i<len;i++)
            Serial.print(buf[i], HEX);
          Serial.println();
        }
    }
 
    // send out any outstanding data
    ble_do_events();
    buf_len = 0;
     
    return; // only do this task in this loop
  }
 
  // process text data
  if (Serial.available())
  {
    byte d = 'Z';
    ble_write(d);
 
    delay(5);
    while(Serial.available())
    {
      d = Serial.read();
      ble_write(d);
    }
     
    ble_do_events();
    buf_len = 0;
     
    return;    
  }
 
  // No input data, no commands, process analog data
  if (!ble_connected())
    queryDone = false; // reset query state
     
  if (queryDone) // only report data after the query state
  { 
    byte input_data_pending = reportDigitalInput();  
    if (input_data_pending)
    {
      ble_do_events();
      buf_len = 0;
       
      return; // only do this task in this loop
    }
   
    reportPinAnalogData();
     
    ble_do_events();
    buf_len = 0;
     
    return;  
  }
     
  ble_do_events();
  buf_len = 0;
}

Il video dimostrativo

Lascio alla tua fantasia la possibilità di inventare tanti progetti con questa shield e di suggerirceli nei commenti !!!